Response spectrum curve is the base of seismic design of structures, and mode-superposition response spectrum method is a practical design method of structures. Damping adjustment factors and shape parameters have been adjusted in the new Chinese code (2010) for damping rate is not equal to 0.05. Then, a new mode superposition response spectrum method combined with continuum method is introduced in this paper. Finally, the earthquake shear of a shear-wall structure’s bottom is calculated, and the results of the new method are compared with that of traditional method implemented in PM-SATWE software which is widely used in architectural design institute. The contrast results show that the new method is available and has a good accuracy.